Stem cells are pluripotent cells derived from somatic tissue capable of differentiating into more specialized cells. For example, hematopoietic stem cells can differentiate into many different types of blood cells, including red blood cells, platelets, and leukocytes.
Hematopoietic stem cells play a role in the continuous lifelong physiological replenishment of blood cells. Stem cells develop into both hematopoietic lineage cells and non-hematopoietic, tissue specific cells. Recently, stem cells have been found to differentiate into a variety of tissue-specific cell types, such as myocytes, hepatocytes, osteocytes, glial cells, and neurons. For example, stem cells have been shown to cross the blood-brain barrier (Willams and Hickey, Curr. Top. Microbiol. Immunol. 202:221-245, 1995) and differentiate into neurons (Mezey, Science 290:1779-82, 2000). Thus, it is possible that stem cells could be used to treat Parkinson's disease (Polli, Haematologica 85:1009-10, 2000), Alzheimer's disease (Mattson, Exp. Gerontol. 35:489-502, 2000), and traumatic brain injury (Magavi, Nature 405: 892-3, 895, 2000). Stem cells also have been shown to differentiate into fibroblasts or fibroblast-like cells, and to express collagen (Periera et al., Proc. Natl. Acad. Sci. 95:1142-7, 1998). Thus, it is possible that stem cells can be used to treat osteogenesis imperfecta and bone fractures. Peterson et al. (Science 284:1168-70, 1999) also has shown that liver cells can arise from stem cells. Thus, stem cells may be of use in treating a variety of pathologies of the liver, including, but not limited to cirrhosis. In addition, bone marrow derived stem cells have been demonstrated to migrate to the site of a myocardial infarction and form myocardium (Orlic, Nature 410:701-5, 2000). Thus, stem cells may be use in treating myocardial infarction.
Since stem cells are capable of differentiating into a broad variety of cell types, they play an important role in the healing and regenerative processes of various tissues and organs (see Koc et al., Bone Marrow Transplant, 27(3):235-39, 2001). Selectin ligands stimulate the release of stem cells from the bone marrow (Frenette et al., Blood 96:2460-68, 2000).
Many studies suggest that the mobilization, migration and differentiation of bone marrow stem cells in the target tissue constitute a natural phenomenon of healing in the human body (Spencer et al., Thorax 60(1):60-2, 2005; Ishikawa et al., FASEB J. 18(15):1958-60, 2004; Mattsson et al., Transplantation 15; 78(1):154-7, 2004; Thiele J et al., Transplantation 77(12):1902-5, 2004; Cogle et al., The Lancet 363(9419):1432-7, 2004; Deb et al., Circulation 107(9):1247-9, 2003; Korbling et al., N Engl J Med 346(10):738-46, 2002; Adams et al., Blood 102(10):3845-7, 2002; Krause et al., Cell 105(3):369-77, 2001). Mobilized stem cells follow concentration gradients of cytokines released by damaged tissues and migrate on their own into tissues following such gradients. Indeed, the mobilization of bone marrow stem cells induced by cytokines injection has been shown to accelerate the healing the cardiac tissue after acute myocardial infarction. Therefore, simply triggering the mobilization of bone marrow stem cells with an effective and safe consumable can enhance this natural physiological process and provide a potential therapy for various pathologies. Thus, there is a need for compositions that increase stem cell mobilization and trafficking.